Storage device using potential generator

ABSTRACT

A space potential generator includes a transformer formed by magnetically connecting a primary coil and a secondary coil, a feedback control circuit feeding back one terminal of the secondary coil to one terminal of the primary coil to adjust voltage of the secondary coil, an output control portion provided on the other terminal of the secondary coil to impart low frequency vibration to an output of the secondary coil, a static electricity discharger formed of conductive material and provided on the other terminal of the secondary coil via the output control portion, the space potential generator does not have a grounding electrode, a weak current flowing through the secondary coil is 0.002 to 0.2 A, the static electricity discharger is covered with an insulating member to discharge predetermined static electricity to surrounding space, and electric field of target voltage is formed in the surrounding space by the discharged static electricity.

CROSS-REFERENCES TO RELATED APPLICATIONS

This Application claims the benefit of priority and is a Continuationapplication of the prior International Patent Application No.PCT/JP2014/080512, with an international filing date of Nov. 18, 2014,which designated the United States, and is related to the JapanesePatent Application No. 2014-027804, filed Feb. 17, 2014, the entiredisclosures of all applications are expressly incorporated by referencein their entirety herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a space potential generator thatdischarges a static electricity to a space to form an electric field, afreshness-keeping device to keep freshness of food or the like using thespace potential generator, and a fryer provided with the space potentialgenerator.

2. Description of Related Art

Conventionally, preserving food in an electric field is proposed tosuppress bacteria growth and prevent deterioration of the food (Patentdocuments 1 to 3).

The invention described in the patent document 1 aims for performing anelectric field processing evenly to objects. An inner electrode and anouter electrode, which is arranged around the inner electrode, areprovided. An electric field processing area is formed between the innerelectrode and the outer electrode. By applying an AC voltage having thesame polarity to each of the electrodes, a positive electric field and anegative electric field are alternately generated on the electric fieldprocessing area.

In the invention described in the patent document 2, a conductiveelectrode is provided in a refrigerator as a shelf board, and theconductive electrode is connected to a high voltage generator providedoutside the refrigerator. Thus, an electrostatic field is generatedaround the conductive electrode, which is provided as the shelf board.

In the invention described in the patent document 3, a pair ofelectrodes is provided in a storage compartment, and an electric fieldis formed in the storage compartment by applying a voltage to the pairof electrodes.

[Patent Document 1] International Publication No. WO2006/054348

[Patent Document 2] Japanese patent No. 4445594

[Patent Document 3] Japanese Unexamined Patent Application PublicationNo. 2012-207900.

In the inventions described in the patent documents 1 to 3, the electricfield is formed and food is preserved in the electric field. Thus,bacteria growth is suppressed and deterioration of the food isprevented.

However, in the inventions described in the patent documents 1 to 3, theelectric field is formed between the electrodes and the food ispreserved in the electric field formed between the electrodes.Therefore, two or more outputs are necessarily required and a structurebecomes complicated. Furthermore, a size of the space to store the foodis limited because a distance between the electrodes is limited.

In the invention described in the patent document 2, judging from itscircuit configuration, the electric field can be formed only immediatelynear the conductive electrode, which is provided as the shelf board.Therefore, unless the food is in contact with the shelf board, an effectof the electric field cannot be obtained.

In particular, in the inventions described in the patent documents 2 and3, judging from their configurations, the effect can be obtained onlywhen an electrode shelf board is provided entirely in the refrigerator.Therefore, the shelf board having a dimension corresponding to the sizeof the refrigerator should be preliminarily produced and the producedshelf board should be installed on the refrigerator by a welding work orthe like. When post-installing the space potential generator in arefrigerating compartment or the like, cost and time are needed and alarge amount of facility investment is required. In addition, since theelectrode shelf board should be installed in the refrigerator, acapacity of the refrigerator is reduced by the electrode shelf board.

Also in the invention described in the patent document 1, the electricfield is formed only at a space between two or more electrodes.Therefore, a plurality of electrodes having a dimension corresponding tothe size of the refrigerator should be preliminarily produced and theproduced electrodes should be installed to cover whole the refrigerator.Thus, a location to install the electrodes is limited. It is difficultto post-install the electrodes in an existing refrigerator or the like.

In the invention described in the patent documents 1 to 3, currentintensity is high. Therefore, an electromagnetic shield should beinstalled in entire the refrigerator.

Furthermore, in a case of a large-size prefabricated refrigerator or alarge-scale storehouse, a voltage of 5000 to 10000 V is required tosupply electricity to a large-sized electrode shelf board or electrodes.Thus, electricity bill is expensive. In addition, the food to bepreserved is directly placed on the electrode shelf board to which thevoltage of 5000 to 10000 V is applied. Therefore, electricity may becharged on a human body when a worker touches the food.

Furthermore, in the invention described in the patent documents 1 to 3,the electrode shelf board should be installed or a plurality ofelectrodes should be installed at a predetermined interval. Therefore,when installing them, the food in the refrigerator should be temporarilymoved to another place.

Furthermore, in the invention described in the patent documents 1 to 3,an extremely large transformer having a large number of turns isrequired to obtain a necessary output voltage. Therefore, the device asa whole becomes large.

The present invention can solve the above described conventionalproblems. The present invention provides a space potential generator anda freshness-keeping device using the space potential generator enablingto downsize the device as a whole, keep a capacity of the refrigeratorsame as before the space potential generator is installed, and generatean electric field in a wide range.

In addition, the present invention provides a fryer that efficientlyforms an electric field in an oil tub to prevent deterioration of oiland generation of acrylamide, shorten time required for frying, andreduce fat and oil smoke.

BRIEF SUMMARY OF THE INVENTION

A space potential generator concerning an embodiment of the presentinvention comprises: a transformer that is formed by magneticallyconnecting a primary coil and a secondary coil; a feedback controlcircuit that feeds back one terminal of the secondary coil to oneterminal of the primary coil to adjust a voltage of the secondary coil;an output control portion that is provided on the other terminal of thesecondary coil to impart a low frequency vibration to an output of thesecondary coil; and a static electricity discharger that is formed of aconductive material and provided on the other terminal of the secondarycoil via the output control portion, wherein the space potentialgenerator does not have a grounding electrode, a current flowing throughthe secondary coil is a weak current having a range of 0.002 to 0.2 A,the static electricity discharger is covered with an insulating memberhaving a predetermined insulating property suitable for allowing thestatic electricity discharger to discharge a static electricity of apredetermined voltage to a surrounding space, and an electric field of atarget voltage is formed in the surrounding space by the staticelectricity discharged from the static electricity discharger.

A frequency of the low frequency vibration imparted to the staticelectricity discharger can be preferably within a range of 40 to 60 Hz.

A voltage value of the static electricity discharged from the staticelectricity discharger via the insulating member can be specifiedaccording to a size of the space in which the electric field is formedso as to form the electric field capable of applying a voltage of atleast 5 V to the object existed in the surrounding space of the staticelectricity discharger. Therefore, in addition to the voltage valueinputted, values of the transformer, the feedback control circuit andthe output control portion, and a material and a size of the insulatingmaterial can be determined so that the voltage value of the staticelectricity discharged from the static electricity discharger via theinsulating member becomes the specified value.

The material used as the insulating member is not limited. For example,a rubber, a polyethylene (PE), an acrylic, a polycarbonate, a cardboard,a polyethylene terephthalate (PET), and a wood can be used.

Although the static electricity discharger can be completely coveredwith the insulating member, the insulating member can be formed by aplate material having small holes, for example. In this case, a shape ofthe holes is not particularly limited.

The static electricity discharger can be preferably formed by aconductive plate, and the static electricity can be discharged from aplate surface of the conductive plate. In this case, a plurality ofopenings can be preferably formed on the conductive plate.

In the space potential generator of the present invention, since thestatic electricity discharger is covered with the insulating material,corona discharge is not generated from the static electricitydischarger. Therefore, the static electricity discharger is notnecessarily a plate-shape as long as it is conductive. For example, thestatic electricity discharger can be a bar-shape or a liner-shape.

If the static electricity discharger is a plate-shape, the insulatingmember can be formed to sandwich the plate-shape static electricitydischarger from above and below, for example. If the static electricitydischarger is a bar-shape of a liner-shape, the insulating member can beformed as a cylindrical body, for example.

As apparent from the above explanation, a space potential generatorconcerning another embodiment of the present invention comprises: atransformer that is formed by magnetically connecting a primary coil anda secondary coil; a feedback control circuit that feeds back oneterminal of the secondary coil to one terminal of the primary coil toadjust a voltage of the secondary coil; an output control portion thatis provided on the other terminal of the secondary coil to impart a lowfrequency vibration to an output of the secondary coil; and a plate-likestatic electricity discharger that is formed of a conductive materialand provided on the other terminal of the secondary coil via the outputcontrol portion, wherein the space potential generator does not have agrounding electrode, a static electricity is discharged from a platesurface of the plate-like static electricity discharger provided on theother terminal of the secondary coil to a space.

In this case, the low frequency vibration can be preferably within arange of 40 to 60 Hz.

As explained later, the freshness-keeping device can include acompartment for determining a freshness-keeping space formed around thestatic electricity discharger, and can include a fryer so that thestatic electricity discharger is installed in an oil tub of the fryer.

A freshness-keeping device concerning the present invention comprises: aspace potential generator; and a compartment for determining afreshness-keeping space formed around the static electricity dischargerof the space potential generator, wherein the space potential generatorcomprising: a transformer that is formed by magnetically connecting aprimary coil and a secondary coil; a feedback control circuit that feedsback one terminal of the secondary coil to one terminal of the primarycoil to adjust a voltage of the secondary coil; an output controlportion that is provided on the other terminal of the secondary coil toimpart a low frequency vibration to an output of the secondary coil; anda static electricity discharger that is formed of a conductive materialand provided on the other terminal of the secondary coil via the outputcontrol portion, wherein the space potential generator does not have agrounding electrode, a current flowing through the secondary coil is aweak current having a range of 0.002 to 0.2 A, the static electricitydischarger is covered with an insulating member having a predeterminedinsulating property suitable for allowing the static electricitydischarger to discharge a static electricity of a predetermined voltageto a surrounding space, and an electric field of a predetermined voltageis formed in a surrounding space by the static electricity dischargedfrom the static electricity discharger, and the electric field is formedin the freshness-keeping space by discharging the static electricityfrom the static electricity discharger of the space potential generatorto keep a freshness of a food in the freshness-keeping space.

A voltage value of the static electricity discharged from the staticelectricity discharger via the insulating member can be specifiedaccording to a size of the freshness-keeping space so as to form theelectric field capable of applying a voltage of at least 5 V to theobject such as food existed in the freshness-keeping space. Therefore,in addition to the voltage value inputted, values of the transformer,the feedback control circuit and the output control portion, and amaterial and a size of the insulating material can be determined so thatthe voltage value of the static electricity discharged from the staticelectricity discharger via the insulating member becomes the specifiedvalue.

The static electricity discharger can be preferably formed by aconductive plate, and the static electricity can be discharged from aplate surface of the conductive plate. In this case, a plurality ofopenings can be preferably formed on the conductive plate.

In the space potential generator of the freshness-keeping device of thepresent invention, since the static electricity discharger is coveredwith the insulating material, corona discharge is not generated from thestatic electricity discharger. Therefore, the static electricitydischarger is not necessarily a plate-shape as long as it is conductive.For example, the static electricity discharger can be a bar-shape or aliner-shape.

If the static electricity discharger is a plate-shape, the insulatingmember can be formed to sandwich the plate-shape static electricitydischarger from above and below, for example. If the static electricitydischarger is a bar-shape of a liner-shape, the insulating member can beformed as a cylindrical body, for example.

The compartment for determining the freshness-keeping space can beanything as long as it has an inside space capable of storing the foodor the like. For example, the compartment for determining thefreshness-keeping space can be a home-use refrigerator/freezer, abusiness-use large-size prefabricated refrigerator/freezer, a foodstorage and a store. The object stored in the freshness-keeping spacefor keeping freshness is not limited to the food. The object can beanything such as oil. In this case, the compartment for determining thefreshness-keeping space is formed by the fryer.

The insulating member covering the static electricity discharger of thespace potential generator can be an insulating member of exclusive use.Otherwise, a housing or a wall surface of the refrigerator and thefreezer forming the compartment for determining the freshness-keepingspace can be used as an insulating material, for example. Specifically,in a case of the refrigerator, for example, the static electricitydischarger is embedded in a peripheral wall or an inside partition wallof the refrigerator.

A fryer provided with the space potential generator concerning thepresent invention comprises: a space potential generator; and a fryerhaving an oil tub, wherein the space potential generator comprising: atransformer that is formed by magnetically connecting a primary coil anda secondary coil; a feedback control circuit that feeds back oneterminal of the secondary coil to one terminal of the primary coil toadjust a voltage of the secondary coil; an output control portion thatis provided on the other terminal of the secondary coil to impart a lowfrequency vibration to an output of the secondary coil; and a staticelectricity discharger that is formed of a conductive material andprovided on the other terminal of the secondary coil via the outputcontrol portion, wherein the space potential generator does not have agrounding electrode, a current flowing through the secondary coil is aweak current having a range of 0.002 to 0.2 A, an electric field of apredetermined voltage is formed in a surrounding space of the staticelectricity discharger by the static electricity discharged from thestatic electricity discharger, and the electric field is formed in theoil tub of the fryer by installing the static electricity discharger inthe oil tub of the fryer.

The static electricity discharger can be covered with an insulatingmember having a predetermined insulating property suitable for allowingthe static electricity discharger to discharge a static electricity of apredetermined voltage to the oil in the oil tub.

The space potential generator of the present invention includes: atransformer that is formed by magnetically connecting a primary coil anda secondary coil; a feedback control circuit that feeds back oneterminal of the secondary coil to one terminal of the primary coil toadjust a voltage of the secondary coil; an output control portion thatis provided on the other terminal of the secondary coil to impart a lowfrequency vibration to an output of the secondary coil; and a staticelectricity discharger that is formed of a conductive material andprovided on the other terminal of the secondary coil via the outputcontrol portion, wherein the space potential generator does not have agrounding electrode, a current flowing through the secondary coil is aweak current having a range of 0.002 to 0.2 A, the static electricitydischarger is covered with an insulating member having a predeterminedinsulating property suitable for allowing the static electricitydischarger to discharge a static electricity of a predetermined voltageto a surrounding space, and the electric field of a target voltage isformed in a surrounding space of the static electricity discharger bythe static electricity discharged from the static electricitydischarger. Therefore, high voltage can be generated on the secondarycoil side by the action of the feedback control circuit and the outputcontrol portion. In addition, since delay is caused in the output of thesecondary coil, the low frequency vibration is imparted to the output ofthe secondary coil. From the above, the static electricity dischargerprovided on the other terminal of the secondary coil is physicallyvibrated at a low frequency. Since the space potential generator of thepresent invention does not have a grounding electrode and the staticelectricity discharger is covered with the insulating material, coronadischarge is not generated. Therefore, the static electricity generatedaround the static electricity discharger is not discharged by insulationbreakdown, and the static electricity is spread in the space by afluctuation of the low frequency vibration. As a result, the electricfield can be formed in a wide range.

From the above, the voltage of the predetermined value is directlyapplied to the object placed in the electric field formed around thestatic electricity discharger. Thus, an effect of keeping freshness ofthe object can be obtained.

Since a periphery of the static electricity discharger is covered withthe insulating member, the static electricity discharger does notgenerate corona discharge regardless of the shape of the staticelectricity discharger. Thus, the shape of the static electricitydischarger can be determined without limitation.

Although there is no risk of an electric shock even if a person touchesthe static electricity discharger because the current flowing in thesecondary coil is the weak current having a range of 0.002 to 0.2 A inthe space potential generator of the present invention, a sense ofsecurity is increased remarkably by covering a periphery of the staticelectricity discharger with the insulating member compared to the statethat the static electricity discharger is barely exposed. Furthermore,even if current of high value is flowed in the secondary coil by somemistake, there is no risk of an electric shock caused by direct contact.From the above, safety is improved because a risk of the electric shockto a human body can be completely eliminated not only when using thedevice but also when installing and transferring the device.

At least 5 V of voltage should be directly applied the object to obtainan effect of keeping freshness. Therefore, a voltage value of the staticelectricity discharged from the static electricity discharger via theinsulating member can be specified according to a size of the space inwhich the electric field is formed so as to form the electric fieldcapable of applying a voltage of at least 5 V to the object existed inthe surrounding space of the static electricity discharger.

In the space potential generator of the present invention, the voltageof the secondary coil is adjusted by feeding back one terminal of thesecondary coil to one terminal of the primary coil by using the feedbackcontrol circuit. As a result, the devise itself can be downsized.

The static electricity discharger is formed by the conductive plate, andthe static electricity is discharged from the plate surface of theconductive plate. Therefore, an area of discharging the staticelectricity in the static electricity discharger can be increased. As aresult, the electric field can be formed in a wider range.

The freshness-keeping device of the present invention includes: a spacepotential generator; and a compartment for determining afreshness-keeping space formed around the static electricity dischargerof the space potential generator, wherein the space potential generatorincludes: a transformer that is formed by magnetically connecting aprimary coil and a secondary coil; a feedback control circuit that feedsback one terminal of the secondary coil to one terminal of the primarycoil to adjust a voltage of the secondary coil; an output controlportion that is provided on the other terminal of the secondary coil toimpart a low frequency vibration to an output of the secondary coil; anda static electricity discharger that is formed of a conductive materialand provided on the other terminal of the secondary coil via the outputcontrol portion, wherein the space potential generator does not have agrounding electrode, a current flowing through the secondary coil is aweak current having a range of 0.002 to 0.2 A, the static electricitydischarger is covered with an insulating member having a predeterminedinsulating property suitable for allowing the static electricitydischarger to discharge a static electricity of a predetermined voltageto a surrounding space, and an electric field of a target voltage isformed in a surrounding space by the static electricity discharged fromthe static electricity discharger, and the electric field is formed inthe freshness-keeping space by discharging the static electricity fromthe static electricity discharger of the space potential generator tokeep a freshness of a food in the freshness-keeping space. Therefore,the voltage can be directly applied to the object such as the food inthe freshness-keeping space even if the object is not directly contactwith the static electricity discharger. As a result, freshness keepingperiod of the food can be extended and bacteria growth can besuppressed.

Since the low frequency vibration is imparted to the output of thesecondary coil in the space potential generator, the static electricitydischarger provided on the other terminal of the secondary coil side isphysically vibrated at a low frequency. In addition, a groundingelectrode is not provided and the static electricity discharger iscovered with the insulating member. From the above, the staticelectricity generated around the static electricity discharger is notdischarged by insulation breakdown, and the static electricity is spreadin the space by a fluctuation of the low frequency vibration to form theelectric field in a wide range. Thus, the electric field can beefficiently formed in whole the freshness-keeping space.

Specifically, if the freshness-keeping device of the present inventionis a refrigerator having a refrigerating compartment, a freezingcompartment and a chilling compartment, for example, by installing thestatic electricity discharger in the refrigerating compartment, theelectric field can be formed also in the other compartments (thefreezing compartment and the chilling compartment) using circulation ofcold air.

The freshness-keeping device of the present invention can be formed byinstalling the space potential generator in an existing refrigerator.Otherwise, the space potential generator can be installed on arefrigerator in a manufacturing process of the refrigerator, forexample. In this case, the static electricity discharger is embedded ina wall or a partition of the refrigerator, and the wall or the partitionof the refrigerator functions as the insulating member. Therefore, theinsulating member for exclusive use is not required and thereforemanufacturing cost can be reduced. In addition, an outer appearance isimproved because the static electricity discharger is embedded in thewall or the partition and unevenness is not generated inside the staticelectricity discharger, being different from the case where the staticelectricity discharger is post-installed.

The compartment for determining the freshness-keeping space can beanything as long as it has an inside space capable of storing the foodor the like. For example, the compartment for determining thefreshness-keeping space can be a home-use refrigerator/freezer, abusiness-use large-size prefabricated refrigerator/freezer, a foodstorage and a store. In any cases, since the voltage of thepredetermined value is directly applied to the object placed in thefreshness-keeping space, freshness of the object can be kept andbacteria growth can be suppressed.

The object stored in the freshness-keeping space for keeping freshnessis not limited to the food. The object can be anything such as oil. Inthis case, the compartment for determining the freshness-keeping spaceis formed by the fryer, and freshness of the oil stored in the fryer canbe kept.

The fryer provided with the space potential generator of the presentinvention includes: a space potential generator; and a fryer having anoil tub, wherein the space potential generator comprising: a transformerthat is formed by magnetically connecting a primary coil and a secondarycoil; a feedback control circuit that feeds back one terminal of thesecondary coil to one terminal of the primary coil to adjust a voltageof the secondary coil; an output control portion that is provided on theother terminal of the secondary coil to impart a low frequency vibrationto an output of the secondary coil; and a static electricity dischargerthat is formed of a conductive material and provided on the otherterminal of the secondary coil via the output control portion, whereinthe space potential generator does not have a grounding electrode, acurrent flowing through the secondary coil is a weak current having arange of 0.002 to 0.2 A, an electric field of a predetermined voltage isformed in a surrounding space of the static electricity discharger bythe static electricity discharged from the static electricitydischarger, and the electric field is formed in the oil tub of the fryerby installing the static electricity discharger in the oil tub of thefryer. Therefore, deterioration of the oil can be suppressed, generationof impurities can be reduced, time required for frying can be reduced,fried food can be prevented from being colored due to deterioration ofoil, odor can be prevented from being transferred to the food, oil smokein the kitchen is prevented, and odor can be prevented from beingtransferred to the cloths.

The static electricity discharger can be covered with an insulatingmember having a predetermined insulating property suitable for allowingthe static electricity discharger to discharge a static electricity of apredetermined voltage to the oil in the oil tub. Since the staticelectricity discharger is covered with the insulating member, a sense ofsecurity is increased remarkably compared to the state that the staticelectricity discharger is barely exposed. Furthermore, even if currentof high value is flowed in the secondary coil by some mistake, there isno risk of an electric shock caused by direct contact. From the above,safety is improved because a risk of the electric shock to a human bodycan be completely eliminated not only when using the device but alsowhen installing and transferring the device.

The static electricity discharger is formed by the conductive plate andthe static electricity is discharged from the plate surface of theconductive plate. Therefore, an area of discharging the staticelectricity in the static electricity discharger can be increased. As aresult, the electric field can be formed in a wider range.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram showing a configuration of a space potentialgenerator of the present invention.

FIG. 2 is a table showing a result of a thawing test of food using aspace potential generator 1 in which a static electricity discharger isnot covered with an insulating material.

FIG. 3 is a table showing a result of an ordinary temperaturepreservation test of food using the space potential generator 1 in whichthe static electricity discharger is not covered with the insulatingmaterial.

FIG. 4 is a table showing a result of an ordinary temperaturepreservation test of food using the space potential generator 1 in whichthe static electricity discharger is not covered with the insulatingmaterial.

FIG. 5 is a table showing a result of an ordinary temperaturepreservation test of food using the space potential generator 1 in whichthe static electricity discharger is not covered with the insulatingmaterial.

FIG. 6 is a table showing a result of an ordinary temperaturepreservation test of food using the space potential generator 1 in whichthe static electricity discharger is not covered with the insulatingmaterial.

FIG. 7 is a table showing a result of a comparative test for an effectof preventing bacteria growth by using the space potential generator ofthe present invention.

FIG. 8 is a graph showing a result of a test for an effect in a frozenstate of food or the like below the freezing point using the spacepotential generator of the present invention. A vertical axis shows aforce applied to the food, and a horizontal axis shows a time.

FIG. 9 shows a result of comparative test for an amount of dripping ofthe thawed food frozen in the electric field using the space potentialgenerator of the present invention.

FIG. 10 shows a thawed state of a fresh-water fish frozen in theelectric field using the space potential generator of the presentinvention.

FIG. 11A is a schematic longitudinal cross-section view of arefrigerator provided with a space potential generator 1. FIG. 11B is aschematic section view along line A-A of FIG. 11A.

FIG. 12 is a schematic front view of a prefabricated refrigeratorprovided with the space potential generator 1.

FIG. 13 is a schematic side view of a refrigerator car provided with thespace potential generator 1.

FIG. 14 is a schematic top view of a store provided with the spacepotential generator 1.

FIG. 15A and FIG. 15B show an example of a supporting member to installa static electricity discharger 8 of the space potential generator 1.

FIG. 16 is a table showing a result comparing a frozen state in thespace potential generator 1.

FIG. 17 shows an example that the static electricity discharger 8 isinstalled in an oil tub 80.

FIG. 18 is a table showing a difference of color in a comparative testof deterioration of oil using the space potential generator of thepresent invention.

FIG. 19 shows a state of oil after 200 g of potatoes are fried comparinga fryer equipped with the space potential generator with a fryer notequipped with the space potential generator.

FIG. 20 is a graph showing a peroxide value of oil after three daystest.

FIG. 21 is a graph showing a result measuring an amount of acrylamidecontained in fried potatoes when 100 g of potatoes are additionallyfried after the three days test.

FIG. 22 is a graph showing a comparative result of frying time.

DETAILED DESCRIPTION OF THE INVENTION

Hereafter, with reference to drawings, an embodiment of a spacepotential generator, and a freshness-keeping device provided with thespace potential generator of the present invention will be explained.Note that the space potential means, for example, a potential differenceand a voltage value measured in the air.

FIG. 1 is a circuit diagram showing a configuration of a space potentialgenerator of the present invention.

As shown in the figure, a space potential generator 1 includes atransformer 4, which is formed by magnetically connecting a primary coil2 and a secondary coil 3.

A terminal 3 a, which is one terminal of the secondary coil 3, isconnected to a terminal 2 a, which is one terminal of the primary coil2, via a feedback control circuit 5 for adjusting a voltage of thesecondary coil 3. The other terminal (i.e. output terminal) 3 b of thesecondary coil 3 is connected to a static electricity discharger 8 viaan output control portion 6 for applying a low frequency vibration tothe output.

In FIG. 1, a reference numeral 7 indicates an AC input plug.

The static electricity discharger 8 is formed of a conductive material.A shape of the static electricity discharger 8 can be a bar-shape, aplate-shape, and a curved plate-shape.

If the static electricity discharger 8 is a plate-shape, a plurality ofopenings, slits or the like can be preferably formed so as not toobstruct air flow in the installed space.

Furthermore, a periphery of the static electricity discharger 8 iscovered with an insulating member 9. If the static electricitydischarger is a plate-shape, the insulating member 9 can be formed tosandwich the plate-shape static electricity discharger from above andbelow, for example. If the static electricity discharger is aliner-shape or a bar-shape, the insulating member 9 can be formed as acylindrical body so as to insert the static electricity discharger intoit, for example. An insulation performance of the insulating member isdetermined based on a voltage value of the static electricity discharger8, a size of the space of the electric field formed by grounding thestatic electricity discharger 8, and a target value of the voltagedirectly applied to the object placed in the space. Specifically, thetarget value of the voltage is preferably 5 V or more. In other words,the insulating member does not completely insulate the staticelectricity discharger. A material and a thickness of the insulatingmember can be determined so as to form a static electricity of apredetermined voltage required for forming an electric field fordirectly applying a voltage of the target value to the object.

By using the space potential generator 1 configured as explained above,a current generated on the side of the secondary coil 3 is fed back tothe primary coil 2 by the feedback control circuit 5. Therefore, highvoltage can be obtained on the side of the secondary coil 3 even if thenumber of turns of the coil is small.

In addition, the feedback control circuit 5 and the output controlportion 6 are formed to cause a delay in the circuit. As a result, lowfrequency vibration is applied to the output of the secondary coil 3. Avibration frequency of the low frequency vibration applied to the staticelectricity discharger, which is the output of the secondary coil 3, ispreferably 40 to 60 Hz. However, the range is not limited to the aboverange. For example, low frequency range can be expanded.

From the above, the static electricity discharger is vibrated at a lowfrequency, and the vibration is transferred to the space around thestatic electricity discharger as a fluctuation. In addition, a groundingelectrode is not provided and the static electricity discharger iscovered with the insulating material. Therefore, the static electricitydischarged from the static electricity discharger is spread widely inthe space around the static electricity discharger by the fluctuation,and the electric field of a predetermined voltage is formed on the spacearound the static electricity discharger.

In the space potential generator 1 of the present invention, highvoltage is generated at the output of the secondary coil 3 by thefeedback control circuit 5 and the output control portion 6, and the lowfrequency vibration is added to the output of the secondary coil 3. Inaddition, the output is only one line of a terminal 3 b, and a groundingelectrode is not provided. Therefore, the static electricity generatedaround the static electricity discharger 8 is not discharged byinsulation breakdown, and electric charge is propagated and spread inthe space by the fluctuation of the low frequency vibration. Thus, theelectric field can be widely formed. Since the static electricity iswidely discharged from the static electricity discharger 8, the electricfield of high voltage is formed around the static electricity discharger8. Specifically, the electric field is formed in a range of a radius ofapproximately 1.5 m around the static electricity discharger 8. If coldair or wind is provided, the electric charge is spread widely andtherefore the area of the electric charge can be spread.

Since the static electricity discharger is covered with the insulatingmember, a sense of security is increased remarkably compared to thestate that the static electricity discharger is barely exposed.Furthermore, even if a current of high value is flowed in the secondarycoil by some mistake, there is no risk of an electric shock caused bydirect contact and there is no possibility of corona discharge.

In the above described space potential generator 1, only by installingone output line and one static electricity discharger 8 in an arbitraryplace such as a freezer, a refrigerator, a thawing chamber, a showcase,a food preservation chamber, an ISO container, a transport truck, anordinary-temperature warehouse, and a refrigerator or a freezer in afishing boat, an electric field of high voltage can be formed in wholethe space (case, room or vehicle) in which the static electricitydischarger 8 is installed. Therefore, freshness-keeping function usingthe electric field can be cheaply and easily added to the desired place.

If the static electricity discharger is embedded in a wall, a ceilingand/or a partition plate when producing the freezer, the refrigerator,the thawing chamber, the showcase, the food preservation chamber, theISO container and the ordinary-temperature warehouse, thefreshness-keeping function can be preliminarily added to the freezer,the refrigerator, the thawing chamber, the showcase, the foodpreservation chamber, the ISO container and the ordinary-temperaturewarehouse. In this case, since the static electricity discharger isembedded in the wall, the ceiling and/or the partition plate, an outerappearance is improved and a sense of security is increased compared tothe state that the static electricity discharger is barely exposed. Inaddition, since the wall, the ceiling and/or the partition platefunction as the insulating material, the insulating material forexclusive use is not required. Furthermore, even if a current of highvalue is flowed by mistake, there is no risk of an electric shock.

In a case of a large warehouse, a plurality of shelves having a lengthof 8 m or more is installed in the warehouse, and the shelves can bemoved to the right and left so that the pallets placed on the shelvesare easily taken out from the shelves by a forklift when shipping. Inthe above described space potential generator 1, since the staticelectricity discharger 8 is separate from a shelf board, even if theshelves are movable as described above, the static electricitydischarger 8 can be easily installed.

In addition, batteries can be used as an electric power source. In thiscase, the static electricity discharger 8 is portable for three days byusing sixteen size D batteries connected in parallel. In addition, thebatteries can be used in combination with an AC power source.

In the above described electric field, the static electricity discharger8 is vibrated at a low frequency and the fluctuation is transferred inthe space. Therefore, the static electricity is spread by thefluctuation and the voltage of a predetermined value or more is appliedto whole the space. Even if the food to be preserved is not in contactwith the static electricity discharger 8, the voltage of 5 V or more isdirectly applied to the object such as the food to be preserved. Thus,an oxidation inhibition effect can be obtained by charging negativeelectron and positive electron, and a bacteria growth suppressing effectcan be obtained by high voltage.

In addition, the food is not frozen even below the freezing point in theelectric field. For example, chicken is not frozen until a temperatureof −3° C., and beef and pork are not frozen until a temperature of −4°C. Thus, the food can be preserved at a low temperature without beingfrozen. From the above, tissue destruction, which occurs when thawingthe frozen object, can be prevented. Thus, the object can be preservedfor a long period without being frozen while keeping freshness.

The voltage of the electric field is high at a place near the staticelectricity discharger 8, and becomes lower as being distant from thestatic electricity discharger 8. A weak electric field is enough forsome objects to be preserved, while a high electric field is requiredfor the other objects. Therefore, the best effect can be obtained byarranging the static electricity discharger 8 on a suitable placeaccording to a preservation place and a configuration of the case.

In the conventional electric field forming device, when forming theelectric field in a home-use refrigerator or a business-use refrigeratordivided into a plurality of compartments, such as a refrigeratingcompartment, a vegetable compartment and a freezing compartment, theelectrode shelf board should be installed on each of the compartments ora pair of electrodes should be installed on each of the compartments.However, in the space potential generator 1 of the present invention,the static electricity discharger 8 becomes an antenna and a highvoltage can be applied to whole the space. Therefore, even if the foodto be preserved is not in contact with the static electricity discharger8, an oxidation inhibition effect can be obtained for the food to bepreserved by charging negative electron and positive electron, and abacteria growth suppressing effect can be obtained for the food to bepreserved by high voltage. Even if the static electricity discharger 8is not provided in each of the compartments, only by installing onestatic electricity discharger 8 on the center, an oxidation inhibitioneffect can be obtained in whole the refrigerator by charging negativeelectron and positive electron together with the cold air, and abacteria growth suppressing effect can be obtained in whole therefrigerator by the high voltage.

If the temperature is adjusted to increase amino acid, aging of the foodsuch as meat can be accelerated. The meat is normally matured for morethan 15 days. Therefore, a special equipment is required for suppressingbacteria and controlling a humidity during such a period. In addition,strict management by a specialist is required. If the space potentialgenerator 1 is installed, bacteria are suppressed and the best effect ofaging can be obtained in a short time. If the space potential generator1 is installed in the conventional refrigerator, tons of beef, pork andchicken can be aged and preserved in a short time and at a low cost.

FIG. 2 is a table showing a result of a thawing test of food using theabove described space potential generator 1. Note that the staticelectricity discharger was not covered with the insulating material inthe test because the test was for confirming the effect of keepingfreshness in the electric field, not the effect of safety and outerappearance.

In the test, three static electricity discharger 8 were installed oneach of longitudinal side walls of a thawing chamber having an innerdimension of 6 m×6 m×3 m at an interval of 2 m at a height of 1.5 m, theelectric field having a spatial voltage of 1 V was formed in the thawingchamber by the static electricity discharged from the static electricitydischarger 8, and the space potential generator 1 was adjusted so thatthe voltage of 10 V was applied to the food placed inside. A dimensionof the static electricity discharger 8 was width 30 cm×height 15 cm.

A temperature in the thawing chamber was 5° C. and a humidity in thethawing chamber was 65%.

In the above described conditions, 2 tons of beef, 1 ton of pork and 1ton of chicken were thawed taking 12 to 15 hours. When the spacepotential generator 1 of the present invention was not installed,dripping was seen all over the floor. On the other hand, when the spacepotential generator 1 is installed, the dripping was reduced by 95%. Byinstalling the space potential generator 1, substantial and tastyprotein, peptide, amino acid, lactic acid, vitamin B complex and varioussalts, which are included in the dripping, can be prevented from flowingout although they usually flew out when thawing the food. In addition,profitability could be increased by avoiding weight reduction, cleaningwork could be reduced, and working process of hygiene management couldbe improved.

FIGS. 3 to 6 are tables showing a result of an ordinary temperaturepreservation test of food using the above described space potentialgenerator 1. Note that the static electricity discharger was not coveredwith the insulating material in the test because the test was forconfirming the effect of keeping freshness in the electric field, notthe effect of safety and outer appearance.

In all the tests, two static electricity discharger 8 were installedside by side on each of longitudinal side walls of a thawing chamberhaving an inner dimension of depth 5 m×width 6 m×height 2.5 m at aheight of 1.5 m, the electric field having a spatial voltage of 20 V wasformed in the thawing chamber by the static electricity discharged fromthe static electricity discharger 8, and the space potential generator 1was adjusted so that the voltage of 30 V was applied to the food placedinside. A dimension of the static electricity discharger 8 was width 30cm×height 15 cm.

A temperature in the thawing chamber was 15° C., a humidity in thethawing chamber was 35%, and a preservation period was 10 days.

In the above described condition, a comparison is performed between thecases of with and without the space potential generator 1.

FIG. 3 is a table showing a result of banana, cucumber and eggplant.

In the case with the space potential generator 1, the banana could beeaten even after 10 days because color was changed little and bananafresh was not oxidized. On the other hand, in the case without the spacepotential generator 1, the banana could not be eaten after 5 daysbecause the color was completely turned brown and banana fresh wasoxidized.

In the case with the space potential generator 1, the cucumber could beeaten even after 10 days because moisture and freshness were kept. Onthe other hand, in the case without the space potential generator 1, thecucumber could not be eaten after 4 days because the cucumber wasoxidized, discolored, and moisture inside was lost.

In the case with the space potential generator 1, the eggplant could beeaten after 10 days because the eggplant was not oxidized although alittle dried. On the other hand, in the case without the space potentialgenerator 1, the eggplant could not be eaten after 5 days because theeggplant was dried and oxidized.

FIG. 4 is a table showing a result of green pepper, carrot, broccoli andChinese cabbage.

In the case with the space potential generator 1, the green pepper couldbe eaten after 10 days because moisture was kept inside although alittle shriveled. On the other hand, in the case without the spacepotential generator 1, the green pepper could not be eaten after 5 daysbecause the green pepper shriveled a lot and completely dried.

In the case with the space potential generator 1, the carrot could beeaten after 10 days because moisture inside was kept and color insidewas not changed although color of skin was changed. On the other hand,in the case without the space potential generator 1, the carrot couldnot be eaten after 5 days because color inside was also changed.

In the case with the space potential generator 1, the broccoli could beeaten after 8 days although color was changed to yellow. On the otherhand, in the case without the space potential generator 1, the broccolicould not be eaten after 4 days because color of clusters was changed toblack.

In the case with the space potential generator 1, the Chinese cabbagecould be eaten after 10 days because moisture was kept and leafs werekept crispy. On the other hand, in the case without the space potentialgenerator 1, the Chinese cabbage could not be eaten after 5 days becausethe Chinese cabbage was dried and leafs were completely open.

FIG. 5 is a table showing a result of cabbage, komatsuna (Brassicacampestris), spinach and scallion.

In the case with the space potential generator 1, the cabbage could beeaten after 8 days because a core was kept white. On the other hand, inthe case without the space potential generator 1, the cabbage could notbe eaten after 4 days because the core became black.

In the case with the space potential generator 1, the komatsuna could beeaten after 8 days because many parts were kept green and moisture waskept. On the other hand, in the case without the space potentialgenerator 1, the komatsuna could not be eaten after 4 days because leafswere completely dried and stems were dried.

In the case with the space potential generator 1, the spinach could beeaten after 10 days because many parts were kept green and moisture waskept. On the other hand, in the case without the space potentialgenerator 1, the spinach could not be eaten after 3 days because leafswere completely dried and stems were also dried.

In the case provided with the space potential generator 1, the scallioncould be eaten after 10 days because many parts were kept green andleafs were kept fresh. On the other hand, in the case without the spacepotential generator 1, the scallion could not be eaten after 3 daysbecause the scallion shriveled as a whole.

FIG. 6 is a table showing a result of celery, green onion, lettuce andtomato.

In the case with the space potential generator 1, the celery could beeaten after 6 days because freshness was kept. On the other hand, in thecase without the space potential generator 1, the celery could not beeaten after 3 days because the celery was completely dried.

In the case with the space potential generator 1, the green onion couldbe eaten after 10 days because many parts were kept green and moisturewas kept. On the other hand, in the case without the space potentialgenerator 1, the green onion could not be eaten after 4 days because thegreen onion was completely dried and stems were also dried.

In the case with the space potential generator 1, the lettuce could beeaten after 10 days because moisture was kept. On the other hand, in thecase without the space potential generator 1, the lettuce could not beeaten after 4 days because the lettuce was completely dried and spoilagebegan.

In the case with the space potential generator 1, the tomato could beeaten after 12 days because moisture was kept and inside was kept fresh.On the other hand, in the case without the space potential generator 1,the tomato could not be eaten after 6 days because the moisture was lostalthough an outer appearance was same.

From the above test results, if the space potential generator 1 is used,only by installing the static electricity discharger 8 in the room orthe compartment, good electric field is formed in the room or thecompartment. Thus, it is confirmed that a preservation period of thefood at an ordinary temperature can be extended in the room or thecompartment in which the electric field is formed.

Next, based on FIG. 7, a test for an effect of preventing bacteriagrowth by using the space potential generator of the present inventionwill be explained. In the test, the static electricity dischargercovered with the insulating member was used.

In the test, beef was entered in refrigerators and the number of thebacteria per 1 g of the beef was measured in the 3rd day, the 5th dayand the 7th day. Following four refrigerators were compared:

-   -   a refrigerator (inside temperature 5° C.), without the space        potential generator;    -   a refrigerator (inside temperature 5° C.), with the space        potential generator;    -   a refrigerator (inside temperature 2° C.), with the space        potential generator; and    -   a refrigerator (inside temperature −2° C.), with the space        potential generator.

A humidity of all the refrigerators was 65 to 75%. An inside area of allthe refrigerators was width 80 cm×height 150 cm×depth 50 cm.

The static electricity discharger of the space potential generatorinstalled in the compartment was formed of an electrode having adimension of height 5 cm×width 10 cm and thickness 1 mm. In addition,both sides of the static electricity discharger were covered(sandwiched) with insulating members made of an insulating plastic(polyethylene plate). A dimension of an upper insulating member washeight 12 cm×width 17 cm and thickness 5 mm. A dimension of a lowerinsulating member was height 12 cm×width 17 cm and thickness 4 mm.

A voltage input into the space potential generator was set to 800 V sothat a voltage directly applied to the beef placed in the refrigeratorbecame 30 V.

FIG. 7 is a table showing a result of a comparative test.

From FIG. 7, it was confirmed that the number of bacteria was extremelydifferent between the refrigerator provided with the space potentialgenerator and the refrigerator not provided with the space potentialgenerator. Thus, by installing the space potential generator, bacteriagrowth could be prevented considerably regardless of the temperature.

Conventionally, the food was frozen to keep freshness of the food. Incase the food was not frozen, temperature must be carefully controlled.By using the space potential generator of the present invention,freshness of the food can be very easily controlled because sufficienteffect of preventing bacteria growth can be obtained as described above.

Next, a test for an effect in a frozen state below the freezing pointusing the space potential generator of the present invention will beexplained.

In the test, chicken was entered in a home-use refrigerator providedwith the space potential generator and not provided with the spacepotential generator, an inside temperature was set to −3° C., and afrozen state of the chicken was observed after 48 hours passed.

An inside area of the refrigerator used in the test was width 50cm×height 30 cm×depth 45 cm. The static electricity discharger installedin the refrigerator was formed of an electrode having a dimension of 5cm×10 cm. Both sides of the static electricity discharger were coveredwith an insulating plastic (polyethylene plate).

A dimension of a front side of the insulating member was height 12cm×width 17 cm×thickness 7 mm. A reverse side was height 12 cm×width 17cm and thickness 6 mm.

An input voltage was set to 1000 V so that a voltage directly applied tothe chicken became 20 V.

FIG. 8 is a graph showing a result of the above explained test. Avertical axis shows a force (N) applied to the food, and a horizontalaxis shows a time.

As shown in FIG. 8, the test was performed by pressing a test probetwice each against the chicken frozen by the home-use refrigerator notprovided with the space potential generator and the chicken frozen bythe home-use refrigerator provided with the space potential generator.

From FIG. 8, it was confirmed that the chicken in the refrigerator notprovided with the space potential generator was harder three times ormore than the chicken in the refrigerator provided with the spacepotential generator. In addition, elasticity was completely lost in thechicken in the refrigerator not provided with the space potentialgenerator. On the other hand, elasticity was remained in the chicken inthe refrigerator provided with the space potential generator.

This means that the chicken was frozen in the refrigerator not providedwith the space potential generator, while the chicken is not frozen inthe refrigerator provided with the space potential generator.

From the above, it was confirmed that the food can be preserved in therefrigerator of −3° C. without freezing the food by using the spacepotential generator of the present invention. Therefore, thawing is notrequired and a problem of flowing out flavor caused by tissuedestruction is prevented, for example.

Next, a test for an effect in a frozen state in −7° C. using the spacepotential generator of the present invention will be explained.

In the test, pork, beef and fish were entered in a home-use refrigeratornot provided with the space potential generator, an inside temperaturewas set to −4° C., and the pork, the beef and the fish were taken outafter 48 hours passed. The pork, the beef and the fish were completelyfrozen and could not be cut by a kitchen knife.

An inner area of the above described home-use refrigerator was width 50cm×height 30 cm×depth 45 cm.

The space potential generator was installed on the same home-userefrigerator, pork, beef and fish were entered in the home-userefrigerator, an inside temperature was set to −7° C., and the pork, thebeef and the fish were taken out after 48 hours passed.

The static electricity discharger of the space potential generator usedin the test was formed by an electrode having a dimension of depth 5cm×width 10 cm. Both sides of the static electricity discharger werecovered with acrylic plates (height 10 cm×width 15 cm×thickness 5 mm) asan insulating member. A voltage input into the space potential generatorwas set to 900 V so that a voltage directly applied to the pork, thebeef and the fish placed in the refrigerator became 10 V.

The pork, the beef and the fish taken out of the refrigerator could becut by a kitchen knife.

Furthermore, a test for an effect in a frozen state in −11.7° C. usingthe space potential generator of the present invention will beexplained.

The space potential generator of the present invention was installed ona business-use prefabricated refrigerator having an inner area of width3 m×height 2.5 m×depth 2 m, pork, beef and fish were entered in therefrigerator, an inside temperature was set to −11.7° C., and the pork,the beef and the fish were taken out after 72 hours passed.

The static electricity discharger of the space potential generator usedin the test was formed by an electrode having a dimension of width 36cm×height 16 cm×thickness 1 mm. Both sides of the static electricitydischarger were covered with polycarbonate plates (height 43 cm×width 23cm×thickness 5 mm) as an insulating member. A voltage input into thespace potential generator was set to 2500 V so that a voltage directlyapplied to the pork, the beef and the fish placed in the refrigeratorbecame 30 V.

The pork, the beef and the fish taken out of the refrigerator could becut by a kitchen knife.

Next, a result of a comparative test for a thawed state of the foodfrozen in the electric field using the space potential generator of thepresent invention will be explained.

In the test, chicken was entered in a home-use refrigerator with andwithout the space potential generator, an inside temperature was kept to−18° C., the chicken was preserved for 72 hours to freeze the chicken,the chicken was taken out of the refrigerator, the chicken wasspontaneously thawed for 10 hours, and a state of the chicken wascompared.

An inside area of the home-use refrigerator used in the test was width50 cm×height 30 cm×depth 45 cm. The static electricity discharger of thespace potential generator was formed of an electrode having a dimensionof height 5 cm×width 10 cm×thickness 1 mm. Both sides of the staticelectricity discharger were covered with plastic plates (height 10cm×width 15 cm×thickness 3 mm) A voltage input into the space potentialgenerator was set to 800 V so that a voltage directly applied to thechicken placed in the refrigerator became 20 V.

A weight of the chicken entered in the home-use refrigerator notprovided with the space potential generator was 343.8 g, and 8.9 g ofdripping came out from the chicken after thawing.

A weight of the chicken entered in the home-use refrigerator providedwith the space potential generator was 468.5 g, and 1.8 g of drippingcame out from the chicken after thawing.

FIG. 9 is a figure showing an amount of dripping of the chicken afterthawing.

From the above described test result, it was confirmed that the foodfrozen in the electric field generated by the space potential generatorcould be thawed without destroying cells, and water molecules could befrozen without destroying cells by a cluster effect in the spacepotential generator.

Next, a result of the above described freezing/thawing test usingfresh-water fish will be explained.

In the test, a fresh-water fish stored in a bag was entered in abusiness-use prefabricated refrigerator with and without the spacepotential generator, an inside temperature was kept to −18° C., thefresh-water fish was preserved for 72 hours to freeze the fresh-waterfish, the fresh-water fish was taken out of the refrigerator, thefresh-water fish was spontaneously thawed for 10 hours, and a state ofthe fresh-water fish was compared.

An inside area of the business-use prefabricated refrigerator used inthe test was width 3 m×height 2.5 m×depth 2 m. The static electricitydischarger of the space potential generator was formed of an electrodehaving a dimension of width 36 cm×height 16 cm×thickness 1 mm. Bothsides of the static electricity discharger were covered withpolycarbonate plates (height 43 cm×width 23 cm×thickness 5 mm). Avoltage input into the space potential generator was set to 2500 V sothat a voltage directly applied to the fresh-water fish placed in therefrigerator became 80 V.

The thawed state was compared. The thawed fresh-water fish frozen by therefrigerator not provided with the space potential generator could notbe eaten because fish meat was spoiled emitting bad smell and a largeamount of dripping came out.

On the other hand, the thawed fresh-water fish frozen by therefrigerator provided with the space potential generator could be eatenbecause the fish was fresh without emitting bad smell and dripping waslittle.

FIG. 10 is a figure showing the thawed state of the fresh-water fish.

Also from the above described test result, it was confirmed that thefood frozen in the electric field generated by the space potentialgenerator could be thawed without destroying cells.

Next, with reference to FIGS. 11 to 16, an embodiment of afreshness-keeping device using the space potential generator will beexplained as an application example of the space potential generator 1of the present invention.

FIG. 11A is a schematic longitudinal cross-section view of therefrigerator provided with the space potential generator 1. FIG. 11B isa schematic section view along line A-A of FIG. 11A.

In the figure, the reference numeral 10 indicates the refrigerator.Inside the refrigerator 10 is divided into three spaces by partitionplates 11 and 12. A chilling compartment 13 is formed on the top, arefrigerating compartment 14 is formed on the middle, and a vegetablecompartment 15 is formed on the bottom.

The static electricity discharger 8 of the space potential generator 1is provided inside the partition plate 11 which is located between thechilling compartment 13 and the refrigerating compartment 14. In thiscase, the partition plate 11 functions as the insulating member of thepresent invention. Since the static electricity discharger 8 isinstalled inside the partition plate 11, the electrode is invisible fromoutside and a sense of security is increased. Furthermore, even ifcurrent of high value is flowed in the input side by mistake, there isno risk of directly contacting the electrode and an electric shockcaused by direct contact can be prevented.

By installing the static electricity discharger 8 in this way, a strongelectric field is formed on the chilling compartment 13 and therefrigerating compartment 14 because the static electricity discharger 8is located nearby, and a weak electric field is formed on the vegetablecompartment 15 because the static electricity discharger 8 is distant.Thus, an electric field environment suitable for the food to bepreserved can be obtained.

In addition, if the static electricity discharger 8 is a plate-shape anda plurality of openings or slits is provided, the static electricitydischarger 8 does not prevent air circulation when an air in therefrigerator is circulated by a fan provided in the refrigerator. Thus,the electric field environment in each compartment can be unified.

Although the static electricity discharger 8 is installed inside thepartition plate 11 in the embodiment shown in FIG. 11, a place toinstall the static electricity discharger 8 is not limited to thisembodiment. The static electricity discharger 8 can be installed in anyplace, for example, in a back board, a top board or other partitionboards of the refrigerator 10.

FIG. 12 is a schematic front view of a prefabricated type refrigeratorprovided with the space potential generator 1.

In this embodiment, the static electricity discharger 8 of the spacepotential generator 1 is installed so as to be suspended from a ceilingwall of a prefabricated refrigerator 20. Although not shown in thefigure, the static electricity discharger 8 is covered with theinsulating member.

In this way, by installing the static electricity discharger 8approximately at the center of the prefabricated refrigerator 20, theelectric field can be uniformly formed in the space of the refrigerator.

FIG. 13 is a schematic side view of a refrigerator car provided with thespace potential generator 1.

The reference numeral 30 means the refrigerator car. The refrigeratorcar 30 cools inside a refrigerator 33 by a cooler 31 via a cool air port32.

The static electricity discharger 8 of the space potential generator 1is installed on a ceiling wall of the refrigerator 33. Although notshown in the figure, the static electricity discharger 8 is covered withthe insulating member. In this case, the space potential generator 1 isconnected to a battery of the refrigerator car 30.

FIG. 14 is a schematic top view of a store provided with the spacepotential generator 1.

In a store 40, food display racks 41, 42, 43, 44 of an open type areprovided. The static electricity discharger 8 of the space potentialgenerator 1 is installed on a side wall near the food display racks 41,42, 43, 44. Although not shown in the figure, the static electricitydischarger 8 is covered with the insulating member.

The space potential generator 1 is operated, for example, at night whenthe store 40 is closed so as to form the electric field around the fooddisplay racks 41, 42, 43, 44 and extend a preservation period of thedisplayed food.

FIG. 15A and FIG. 15B show an example of a supporting member to installthe static electricity discharger 8 of the space potential generator 1.Although not shown in the figure, the static electricity discharger 8 iscovered with the insulating member.

FIG. 15A shows a supporting member 51 used for installing the staticelectricity discharger 8 of the space potential generator 1 so as to bevertically standing on a floor 50.

By using the supporting member 51 to support the static electricitydischarger 8 vertically standing on the floor, an installation locationof the static electricity discharger 8 can be more flexibly selected.Thus, the static electricity discharger 8 can be installed on a moreoptimum position.

FIG. 15B shows a supporting member 61 used for installing the staticelectricity discharger 8 of the space potential generator 1 so as to besuspended from a ceiling 60. A leg portion of the supporting member 61is fixed to the ceiling 60 by a suitable fixing means 62.

By using the supporting member 61 to support the static electricitydischarger 8 to be suspended from the ceiling, an installation locationof the static electricity discharger 8 can be more flexibly selected.Thus, the static electricity discharger 8 can be installed on a moreoptimum position.

FIG. 16 is a table showing a result comparing a frozen state in thespace potential generator 1.

Conventionally, a quick freezer of −60° C. was used so as to preventdeterioration of the food and not to destroy cells of the food whenfreezing.

On the other hand, in a prefabricated freezer or a cold storagewarehouse, freezing can be done in the best condition by installing thespace potential generator 1, setting the space potential generator 1 sothat a space potential becomes 1 V and an applied voltage becomes 10 V,and setting a temperature to −18° C.

By installing the space potential generator 1, water molecules can befrozen without destroying cells by a cluster effect. In addition, thefood is not required to be transferred from the quick freezer to thefreezer because freshness keeping can be also done after freezing.Therefore, a cost of facility investment to buy the quick freezer is notrequired. In addition, by installing the space potential generator 1 inthe conventional freezing equipment, electricity cost can be reduced andcarbon dioxide emissions can be reduced.

FIG. 16 is a table showing a result comparing a case in which a mangohaving a size of height 15 cm and width 10 cm is frozen at −60° C. byusing a quick freezer with another case in which the same mango isfrozen at −18° C. by using the space potential generator 1.

In the case the mango was frozen at −60° C., since cold air of quickfreezing was applied to the mango, moisture contained in the mango waslost and a surface was a little dried when cut into halves and compared.On the other hand, moisture was kept in the mango frozen by the spacepotential generator 1.

After that, the mango was left at an ordinary temperature for threehours and then texture was compared. The mango frozen at −60° C. becamedried and hard. On the other hand, the mango frozen by the spacepotential generator 1 could be eaten deliciously because moisture waskept.

When freezing sushi-roll (vinegared rice wrapped in seaweed), freezingis done in units of forty thousand. In the conventional devices, theelectrode shelf board should be prepared and the foods should be incontact with the electrode shelf board. Therefore, a quantity capable ofbeing frozen is limited in the conventional device.

In addition, a large amount of facility investment is required for thequick freezing because a quick freezer for special use is required.

By using the space potential generator 1 of the present invention, sincefreezing can be done in the best condition at −18° C., the quick freezerfor special use is not required. In addition, since the electric fieldis formed in whole the space, the quantity capable of being frozen isnot limited.

Furthermore, the food was frozen at −18° C. in the freezer with andwithout the space potential generator 1 to compare the result. It wasconfirmed that a size of ice crystals adhered to the food after beingfrozen was larger in the freezer not provided with the space potentialgenerator 1. The ice crystals are very small in the refrigeratorprovided with the space potential generator 1 because cluster of watermolecules is made smaller when being frozen. From the above, freezingcan be done in the best condition without destroying fibers of the foodonly by providing the space potential generator 1 in the existingfreezer.

As for the ISO container and the transport truck, the ISO container wasconventionally transported at −20° C. from abroad spending two weeks.However, if the space potential generator 1 is installed, thetransportation is possible in a chilled environment set at −5° C. whilekeeping freshness. From the above, electricity cost can be reduced andcarbon dioxide emissions can be reduced.

Next, an oil deterioration preventing function of a fryer provided withthe space potential generator of the present invention will beexplained.

When the space potential generator 1 is installed on a gas fryer or anelectric flyer and an electric field of 400 V or more is applied, anelectric field environment can be formed in an oil tub of 100 liters byone output line and one static electricity discharger 8.

When the static electricity discharger 8 is installed on a bottomsurface or a side surface of an oil tub of 20 liters single-layer, acertain effect can be obtained.

In a case of a double-layer type gas flyer or electric fryer, when astatic electricity discharger 8 is installed in one of the oil tubs, aneffect of a weak electric field can be obtained even in the neighboringoil tub although the static electricity discharger 8 is not installed inthe neighboring oil tub. Therefore, in the case of the double-layer typegas flyer or electric fryer, the best effect can be obtained byarranging the static electricity discharger 8 at the center of two oiltubs.

Since oxidation of the oil is suppressed by installing the spacepotential generator 1, the oil can be used more than four times longerthan the oil used in the flyer not provided with the static electricitydischarger 8. Since emulsion of the oil and water contained in the foodis suppressed, viscosity of the oil can be easily lowered. Therefore,the oil can be continuously used by replenishing new oil withoutdisposing the oil.

In addition, time required for frying can be shortened by 15%.

Furthermore, since emulsion of the oil and water contained in the foodis suppressed and cluster of water molecules is made smaller by theeffect of the space potential generator 1, thermal conductivity of thefood is increased. Therefore, in the fryer provided with the spacepotential generator 1, a lot of steam can be seen in the oil tub justafter the food was entered. This leads to reduction of oil mist and oilsmoke. Thus, oil smoke is prevented from being absorbed by a worker inthe kitchen and oil is prevented from entering in eyes of the worker. Inaddition, stickiness of the oil can be reduced in the kitchen.Therefore, health and sanitation of the worker can be improved. Sincethe thermal conductivity is increased, the food can be fried in a shorttime and the oil absorbed in the food can be reduced. Conventionally,corndogs and sausages become hard and should be disposed when 3 hourshave passed after they are fried. However, by using the fryer of thepresent invention, they can be eaten deliciously after 12 hours havepassed. Thus, disposal of the food can be reduced.

FIG. 17 shows an example that the static electricity discharger 8 isinstalled in an oil tub 80.

Hereafter, a result of a comparative test about deterioration of oilusing the space potential generator of the present invention.

In this test, two fryers were prepared, 6 liters of oil was entered ineach of the fryers, and the space potential generator was provided onone of the fryers. Same amount of sample food is continuously fried ineach of the fryers and then the oil was compared. Two fryers wereseparated 4 meters with each other so as to avoid an influence of theother fryer.

The static electricity discharger was an electrode of height 5 cm×width10 cm×thickness 1 mm. Both sides of the electrode was covered with theinsulating member (height 7 cm×width 12 cm×thickness 2 mm) formed of aTeflon (registered trademark) (PTFE) material. In addition, 60 holes of4 mm were formed on the insulating member. Wires connected to the staticelectricity discharger were formed of a Teflon (registered trademark)(PTFE) material and had a thermal resistance resistant to a temperatureof 260° C. An input voltage of the space potential generator was set to800 V so that a voltage directly applied to the oil became 800 V.

By the above described fryers, 300 g of chicken (with starch powder) wascontinuously fried until 28 kg of chicken were totally fried, and thencondition of the oil was compared in viewpoints of a color, an odor, anacid value, a peroxide value, and an acrylamide generation amount.

The color was judged by visual observation. The odor was judged based ona sensory evaluation performed by an odor judgment technician, which isa national qualification authorized by the Ministry of the Environment.

The acid value is a reference value generally used for measuringdeterioration in Japan. Although the peroxide value is not a referencevalue generally used for measuring deterioration, the peroxide value wasmeasured for confirming the effect from various aspects.

As for the acrylamide, Food Safety Commission of the Food SafetyCommission of Cabinet Office in Japan now examines a risk of theacrylamide as a chemical substance contained in the food, and evaluatedthe acrylamid as “genotoxic carcinogen” in a draft of evaluation.

In addition, FDA (U.S. Food and Drug Administration) reported in “FDADraft Action Plan for Acrylamide in Food” that the acrylamide having arisk of carcinogenesis and genetic damage could be generated in theprocessed food. Furthermore, on Apr. 24, 2002, a joint research groupconsisting of Swedish National Food Administration and StockholmUniversity published that the food contained the acrylamide when thefood was cooked by frying or grilling a raw material containing a lot ofcarbohydrates at high temperature of 120° C. or more.

As explained above, since the acrylamide can be a carcinogen, theacrylamide generation amount was also confirmed.

In the above described condition, same amount of the food wascontinuously fried in two fryers for three days so as to keep friedstate substantially same. A core temperature after fried was measured bya thermometer so that the core temperature became 75° C.

After the test, the used oil was collected from two fryers and the abovelisted test items were compared. As a result, deterioration wassuppressed in the fryer provided with the space potential generator inall test items of the color, the odor, the acid value, and the peroxidevalue. In addition, it was confirmed that the acrylamide generationamount was reduced to a quarter.

FIG. 18 is a table comparing the color of the oil in the second day.

It was confirmed that lightness was significantly different between theoil of the fryer provided with the space potential generator and the oilof the fryer not provided with the space potential generator. A colordifference between the former and the latter was 6.43.

In FIG. 18, the color difference is a value totally comparing thedifference between the oil before cooking and the oil after cookingusing an L*a*b* color system. Here, L indicates the lightness, +aindicates red, −a indicates green, +b indicates yellow, and −b indicatesblue. According to an NBS (U.S. National Bureau of Standards) unit, acolor difference value (ΔE) is considered to be large when the colordifference value is 6.0 or more. The color of the oil in the fryerprovided with the space potential generator is brighter than the colorof the oil in the fryer not provided with the space potential generator.As explained above, the color difference was 6.43 in the second day.Thus, it was confirmed that the oil was deteriorated more significantlyin the fryer not provided with the space potential generator.

A plurality of inspectors including the odor judgment technician, whichis a national qualification authorized by the Ministry of theEnvironment, evaluated the oil in the fryer provided with the spacepotential generator and the oil in the fryer not provided with the spacepotential generator. As a result, the odor suggestive of fried chickenand the odor considered to be roasted were weak in the former oil thanthe latter oil. Thus, it was confirmed that the odor was lesstransferred to the oil.

Furthermore, when comparing the oil in the fryer provided with the spacepotential generator with the oil in the fryer not provided with thespace potential generator by visual observation, black stains and crabbubbles were seen in the latter oil. In addition, when 200 g of potatoeswere additionally fried in the latter oil after the above test, the oilsmoke when frying the last 100 g of potatoes was like a steam of a bath.Thus, the working environment was deteriorated and sticky stain and badodor were confirmed. In the oil in the fryer provided with the spacepotential generator, the crab bubbles were not seen and oil surface wassmooth.

FIG. 19 shows a state of the oil after 200 g of potatoes were friedcomparing the fryer equipped with the space potential generator with thefryer not equipped with the space potential generator.

FIG. 20 is a graph showing the peroxide value of the oil after threedays test.

While the peroxide value of the oil in the fryer provided with the spacepotential generator was 1.89, the peroxide value of the oil in the fryernot provided with the space potential generator was 2.77. From the aboveresult, it was confirmed that the fryer provided with the spacepotential generator suppressed the deterioration by 32% compared to thefryer not provided with the space potential generator.

FIG. 21 is a graph showing a result measuring an amount of theacrylamide contained in the fried potatoes when 100 g of potatoes wereadditionally fried after the three days test.

The acrylamide contained in the potatoes fried in the fryer not providedwith the space potential generator was 425 μg/kg. On the other hand, theacrylamide contained in the potatoes fried in the fryer provided withthe space potential generator was 113 μg/kg. It was confirmed that theacrylamide generation amount was reduced to a quarter by using the spacepotential generator. Since the acrylamide can be a carcinogen, theacrylamid generated by the deteriorated oil is internationallyrecognized as a problem. Therefore, an effect of suppressing of theacrylamide generation is important.

Next, a result of test comparing the fryer with and without the fryerthe space potential generator by entering 60 g of potatoes in oil tubsof both fryers, setting a temperature to 170° C. to fry the potatoes,and comparing a change of the state of the oil. In the fryer notprovided with the space potential generator, water in the food isentered in the oil by being combined and emulsified with the oil. On theother hand, in the fryer provided with the space potential generator,since the oil is combined with electrons and not combined with thewater, the water in the food is immediately evaporated and not enteredin the oil. Therefore, the temperature of the oil is always keptconstant, and the time required for frying can be shortened. Inaddition, since only the water is evaporated as water vapor in the fryerprovided with the space potential generator, oil mists around the fryercan be reduced. Therefore, the oil is not adhered to the kitchen and thestore, and the kitchen and the store can be kept sanitary. Furthermore,since evaporation of the oil can be suppressed, odor of the oilgenerated when frying the food can be suppressed. For example, the oilis prevented from adhering to cloths of the customers in the store.

Finally, a result of a comparative test of time required for fryingfrozen chicken will be explained.

The time required for frying the frozen chicken was compared between thefryers with and without the space potential generator.

A capacity of the oil tub of both fryers was 6 liters. A temperature wasset to 165° C. A center temperature of the fried chicken was measuredwhen 2 minutes and 30 seconds had passed and when 3 minutes had passedfor comparison.

In the fryer provided with the space potential generator, the centertemperature of the fried chicken was 83.6° C. when 2 minutes and 30seconds had passed, and 95° C. when 3 minutes had passed. On the otherhand, in the fryer not provided with the space potential generator, thecenter temperature of the fried chicken was 34.6° C. when 2 minutes and30 seconds had passed, and 80° C. when 3 minutes had passed. From theabove, it was confirmed that thermal conductivity was higher and thetime required for frying was shorter in the fryer provided with thespace potential generator.

FIG. 22 is a graph showing a comparative result of frying time.

Evaluation in Actual Store

In a store conventionally using 405 liters (22.5 cans) of oil per month,the space potential generator was installed on the fryer and thetemperature of frying was lowered from 180° C. to 170° C. afterinstalling the space potential generator. As a result, the oil used inthe store is reduced to 108 liters (6 cans) per month. The oil used wasreduced by 73%. In addition, the time required for frying was shortenedby 10% or more. Thus, efficiency of work was improved.

If the electric field is formed in the oil in the fryer by using thespace potential generator, the best effect could be obtained becausethermal conductivity of the food was increased and the fried food becamecrispy. Furthermore, the oil smoke was prevented because the water isevaporated. Thus, the worker in the kitchen did not feel pain in eyes.

Note that, this invention is not limited to the above-mentionedembodiments. Although it is to those skilled in the art, the followingare disclosed as the one embodiment of this invention.

-   -   Mutually substitutable members, configurations, etc. disclosed        in the embodiment can be used with their combination altered        appropriately.    -   Although not disclosed in the embodiment, members,        configurations, etc. that belong to the known technology and can        be substituted with the members, the configurations, etc.        disclosed in the embodiment can be appropriately substituted or        are used by altering their combination.    -   Although not disclosed in the embodiment, members,        configurations, etc. that those skilled in the art can consider        as substitutions of the members, the configurations, etc.        disclosed in the embodiment are substituted with the above        mentioned appropriately or are used by altering its combination.

While the invention has been particularly shown and described withrespect to preferred embodiments thereof, it should be understood bythose skilled in the art that the foregoing and other changes in formand detail may be made therein without departing from the sprit andscope of the invention as defined in the appended claims.

What is claimed is:
 1. A storage device for maintaining a freshness ofan object stored therein, comprising: a potential generator; and acompartment for determining a storage space formed around a dischargingelectrode of the potential generator, wherein the potential generatorcomprising: a transformer that is composed of a primary coil and asecondary coil; a feedback control circuit that feeds back one terminalof the secondary coil to one terminal of the primary coil to adjust avoltage of the secondary coil so that high voltage can be obtained on aside of the secondary coil even if a number of turns of the secondarycoil is small; an output control portion that is provided on the otherterminal of the secondary coil to impart a predetermined low frequencyvibration to an output of the secondary coil so that the dischargingelectrode physically vibrates and discharges a static electricity of apredetermined voltage to a surrounding space; and the dischargingelectrode that is formed of a conductive material and provided on theother terminal of the secondary coil via the output control portion,wherein the discharging electrode is shaped as a plate shape, thefeedback control circuit and the output control portion are formed tocause a delay in the circuit so that the low frequency vibration isapplied to the discharging electrode of the secondary coil, a vibrationfrequency of the low frequency vibration applied is 40 Hz to 60 Hz whichis determined by the output control portion, a grounding electrode isnot provided on the potential generator, a current flowing through thesecondary coil is a weak current having a range of 0.002 A to 0.2 A, thestatic electricity is discharged from a surface of the dischargingelectrode provided on the other terminal of the secondary coil to thestorage space, the discharging electrode is covered with an insulatingmember having a predetermined insulating property suitable for allowingthe discharging electrode to discharge the static electricity of thepredetermined voltage to the surrounding space, and an electric field isformed in the storage space by discharging the static electricity fromthe surface of the discharging electrode of the potential generator tokeep the object in the electric field formed in the storage space. 2.The storage device according to claim 1, wherein the dischargingelectrode is consisted of a conductive plate, and a plurality of openingparts is formed on the conductive plate.
 3. The storage device accordingto claim 1, wherein the compartment for determining the storage space isa refrigerator; the discharging electrode of the potential generator isinstalled in the refrigerator; and the refrigerator forms the storagespace.